Scientists May Find Out Exactly What Happened to the Dinosaurs

The sudden extinction of the dinosaurs at the end of the Cretaceous period is one of the biggest head-scratching scientific mysteries of our time. We have a very general idea of how it happened, but the details are still extremely fuzzy, and many scientists disagree on what actually killed off the fearsome animals. Now, scientists are about to drill into the crater from the meteor impact that wiped them out for the very first time, which means those details may be filled in very soon.

According to the prevailing theory of the dinosaur extinction, a huge meteor struck in the Yucatan Peninsula 66 million years ago, releasing an amount of energy equivalent to one billion atomic bombs. Plants and animals in the surrounding areas were killed instantly, and the impact started a chain reaction that led to the extermination of at least 75% of the species on Earth at that time, including the dinosaurs.

However, scientists diverge in their opinions of how exactly the meteor strike caused the mass extinction. Some contend that the impact started a spate of volcanic eruptions that released poisonous gases into the atmosphere for 500,000 years, causing most of the extinctions. Others suggest that the impact triggered natural disasters such as earthquakes and tsunamis, and that the dinosaurs were killed by the resultant debris.

Starting on April 1, scientists will begin drilling into the Chicxulub crater, which is widely believed to be from the meteor that caused the mass extinction event. The aim is to study the "peak ring," the elevated ring that's the mark of the largest impact craters, which lies 1,500 meters below the ocean's surface.

"Chicxulub is the only preserved structure with an intact peak ring that we can get to," co-lead researcher Sean Gulick from the University of Texas at Austin told Science. "All the other ones are either on another planet, or they've been eroded."

The retrieved rock cores from the peak ring could provide evidence for how life rebounded after the extinctions, which may tell us the cause of the extinctions in the first place. If the scientists are able to analyze the genes of the microbes that live in the peak ring, they may be able to determine whether the air surrounding the crater was poisonous. And further, if the microbes have unique metabolic pathways that allow them to derive their energy from iron or sulphur in the rock rather than oxygen, then they could prove that the same meteor that killed the dinosaurs seeded extraterrestrial life on Earth.